Every application has issues, and every newbie programmer wants to
start over from scratch. When they finish, they want to start over
again. "The grass is always greener on the other side" (stateside
saying). Add that to every newbie programmer wants to write "the
perfect programming language", and you know how to spot youthful
exuberance.

Let them get away with it, and you have an example of poor management.

I've seen this approach NOT be a total failure/fiasco once in my 30
years as a programmer (and even that time was questionable, as the
company went broke before going to market with the re-write).

Yes, I do realize this is flame bait, but only from those lacking
programming experience.